SG-615

April 1987

The plastic SMD crystal oscillator that became a de facto standard

The SG-615, released in April 1987, was the quartz device industry's first crystal oscillator to come in a plastic SMD (surface mount device) package. This groundbreaking product opened the door for other SMD-type crystal devices, which up to that time were usually encased in metal packages. The migration to a plastic package was enabled by technology from Epson's semiconductor manufacturing operations. Before an SMD package could be used, researchers needed a crystal unit that would be able to withstand the harsh conditions present in a reflow-soldering system. The breakthrough came with the development of an AT-cut crystal unit sealed in a heat-resistant cylinder. The reference output frequency range was approximately 1 MHz to 26 MHz, and overtone oscillator enabled even higher order frequency. An Epson CMOS IC was used for the oscillation circuit, thus achieving low current consumption.

The SG-615 became a de facto standard product after the dominant personal computer manufacturer of the day started using it as a control clock in its PCs; other PC manufacturers soon followed suit. Epson thus established its position as a leader in SMD products for the quartz device industry. The product lineup has done nothing but grow ever since.